Carburetors, including an auxiliary starting device



United States Patent CARBURETORS, INCLUDING AN AUXILIARYSTARTINGZDEV'ICE Andrv Louis M'ennesson, Neuilly-sur-Seine, France,assignor to Solex S. A., Neuilly sur-Seine, France, a scietyof FranceApplication September 10,1954, Serial No; 455,214

Claims priority, application Fra'uce- September 25, 1953 9 Claims. (Cl.26-1-41) The present inventionfrelatesto. carburetors including anauxiliary starting device capable of delivering fuel toward the engineunder the eifectof the suction existing in the induction pipe thereofdownstream of the carburetor throttle, said' au xiliary device comprisngan independently operated distributing valve for controlling thedelivery of fuel toward the downstream side of the throttle and; meansoperative by said distributing valve for slightly displacing saidthrottle in the opening direction from its maximum closing position whensaid distributing valve is moved into a position in which itdeliversfuel toward the downstream side ofthe throttle, whereby at leastaportion of the air to be mixed with the fuel supplied through saiddistributing valve is admitted through the passage thus afforded-bysaidthrottle.

The object of the present invention is to improve the operation of suchcarburetors, whether their distributing valve is operated manually orautomatically.

They consist chiefly in-providingsuch carburetors with means such that.the sectionoffiow afforded to. the fuel flowing. from the auxiliarystarting device toward theengine induction pipe, downstream of thethrottle, is controlled under the effect of the suction existing atthisplace in said pipe, so as to be reduced when-saidsuction exceeds apredetermined value.

Preferredembodiments. of my invention will be hereinafter described withreference. tov the accompanying drawings, given-merely by way ofexample, and-in which:

Fig. 1 diagrammatically shows, partly in; elevational view. and partly.in sectional View, a carburetor made according to my. invention.

Fig, 1a is a; partial view showing a modification. Fig.v 2 is apartialsection-on the line IIII= of Fig; 1'.

Fig. 3. shows, similarly.- to Fig. l, but in a different relativeposition of theparts a portion of said carburetor.

Figs. 4 and 5 are views similar to Fig; 1. but correspondingto twodifierentrelative:positionsofthe parts, theseviews showing the.distributing valve of. the carburetor.

OmFig. 1,. referenceqcharacter. 1- designates the body fi idfidz 0: he:Stream: ofi mixture: flowing from the; starting; carburetor: towardithe: induction pipe of the engine downstream off? that throttle: is:con-- troll-ail l 'zflfiifln ce qsvariationsrofi-tlreisuetionexistingrin Im the: embodiment of 'ice z saidpipe at this place; in suchmanner asto be reduced when said suction exceeds a predetermined value.

Furthermore, preferably, supplementary means which may be combined withthose just above mentioned arev provided so that the suction exerted onthe fuel" supplied by the auxiliary starting carburetor is reduced whenthe suction existing in the inductionpipe, downstream. of the throttle,exceeds a predetermined' value, which may be the same as that justabjovementioned'.

in the embodiment of Fig, 1, the distributingvalveis constituted by adisc-ofisubstantially cylindrical shape 43.- pivotally mounted about anaxis 44and 'kept by a spring, 45 in fluidtight contact. with a flatsurface provided 0111 the body of the carburetor.

This disc 43is provided with a central recess. andwith three radialgrooves 46 preferably at to eachzother, as shown in: dottedslines on.Figs. 1 4 andS.

An operating lever 47 iS.fiXedto disc- 43 whichaalso carries a cam 20;This cam v is adapted to cooperate as above indicated, with a lever 23freely rotatable Orr-tho spindle of throttle S'and including an.abutment 25: upon which bears an adjustable screw 26 carried by a: lever18 fixed on. the spindle of throttle 5- and; connected with the throttlespindle.

Three conduits or channels open into theflatsurface: which cooperateswith disc 43'.

T he first one is the above mentioned downwardcon duit 14, the. openingof said conduit into said surface communicating, through a calibratedpassage 48; (Fig.- 4.)" with a small recess 49 which-will be hereinaftermore? explicitly referred to.

The second ofithese conduits,. designated by reference" numeral 50,.communicates with a cylindrical chamber 51, which. will alsobe moreexplicitly referred 1 toherein after.

The third of saidconduits, designated by reference character 52,communicates also with said chamber. 51 as it will be hereinafterexplained.

Chamber 51 isformed, preferably vertically, in the body 1 ofthecarburetor;v Itsupper end communicates through a passage- 53-with-; the:main air intake of tlie carburetor and its lower end communicates withthe engine inductionpipe,downstream:ofzthe'th-rottle; through a conduit54, which. extendsmpwardlyin said chamber 51 in the form of a tube 55provided at'its upper'end' with a large area aperture 56 and, its sidewall, with a passage-57 of substantially smaller area. i

A. piston 58-is. slidable in chamber 51- above"tt1be" 55', and'this.piston is urged upwardly by a sprin'g' 59 of suitable characteristics aswill beexplained hereinafter;

The whole is arranged 'insuch manner that-when said piston58-is initslowermostposition, aslshown by Fig. 3, it closes the. large areapassage 56: provided at the-top} of tube55while it opens. the outletofconduit 52- intochamber 51 thus causing: this outlet. to ccmmunicatdthrough passage 53 with the main air intake of the car buretor'.

On theother hand,',when piston 58 is pushed upwardlyby spring 59 (1Fig;l):so. ast-to'be brought in'to co'ntactwitli' its abutment: 60;. said;piston stops the outlet of conduit 52 and simultaneously opens: thelargearea passage 56 of tube 55, thus connecting it with ccndt iit fll.

Conduits 14,: 50. and"52 open into the flat surface of the carburetorbody, which cooperates with disc 43; in? such mannerthat each of thesechannels either be stopped by-disc 4301' on the contrary beplacedirrcbm: munication with one of the three radial grooves, 46 provided indisc 43; accordingto' the" position Qffsaid: disc.

Forinstance; in'Fi'g; l", disc43"isin' a posi'tionsucili that. tli'ethr'ee conduits 14-,"59 a'nd 5'2 communicate freely together throughgrooves 46 and the central recess of disc 43.

On the contrary, in Fig. 4, where disc 43 is shown as having beenslightly rotated in the clockwise direction, conduit 14 is incommunication with the corresponding radial groove of disc 43 onlythrough the small area recess 49, whereas the communication betweenconduits 50 and 52 takes place only through a passage of smallersection.

Finally, in Fig. 5, the three conduits above referred to are fullyseparated from each other.

Of course, the openings of conduits 14, 50 and 52 into the flat surfaceof the carburetor body and/or the grooves of disc 43 are provided insuch manner that, starting from the fully open position of thedistributing valve (starting from cold), as shown by Fig. 1, when saiddistributing valve is gradually closedthe flow of sections supplied bythe distributing valve for the three above mentioned channels alsodecrease gradually until they are fully stopped.

Cam 20 is arranged in such manner that when the distributing valve is inthe fully opened position (Fig. l), throttle is slightly opened whereaswhen the distributing valve is being gradually closed, the throttle isalso gradually returned (Fig. 4) to its idling rimming position (Fig.5).

This device works in the following manner:

It is known that when the engine has to be started from cold it isnecessary to obtain a very rich mixture whereas on the contrary thismixture must very quickly become leaner as soon as the engine has beenstarted.

On the other hand, when the engine is running but before it has reachedits normal temperature of operation, it is necessary to obtain, for allrunning conditions, a mixture which is slightly richer than thatnormally supplied by the normal jet systems of the carburetor.

These conditions can be complied with owing to the provision of piston58 and of the distributing valve constituted by disc 43.

When starting from cold, the elements are in the relative positionsshown by Fig. l. Lever 47 then causes the displacement of lever 23 bycam 20 to be maximum. This lever 23, which acts through its abutment 25on screw 26, actuates lever 18 and throttle 5 to open it to a degreeslightly greater than the normal opening for idling runmng.

The three radial grooves 46 connect together conduits 14, 50 and 52.Piston 53, which is pushed upwardly by a spring, afiords a free passagethrough tube 55 toward conduit 54.

When the engine is driven by the starter, there is produced in theinduction pipe a suction the value of which determines the strength tobe given to spring 59. This spring must be sufficiently strong to keeppiston 55 in upper position despite the action of said suction thereof.

In these conditions, this suction, which is relatively low because ofthe small speed with which the engine is driven by the starter, sucks infuel from well 11 through Elie orifices of tube 13 and through conduits14, Si and As no air inflow is provided to weaken the suction exerted onthe fuel in tube 13, I obtain a mixture as rich as it may be desired andthe richness of which is determined by the choice of jet 12, of thecalibrated air passage provided at the top of well 11 and of theorifices provided in tube 13.

As soon as the engine is running, its speed suddenly increases from100/150 revolutions per minute to at least 700/800 revolutions, andconsequently the suction in the induction pipe and in conduit 54 becomesmuch higher than when the engine was being driven by the starter.

The characteristics of spring 59 must be such that, in these conditions,piston 53 is then moved down by the suction existing in conduit 54 andcloses the large area passage 56 provided at the top of tube 55,allowing fuel to pass only through calibrated hole 57 (Fig. 3).

Simultaneously, the opening of conduit 52 is cleared and air penetrates,under the effect of the suction, through conduit 53, conduit 52 and theradial grooves 46 of the distributing valve, this air being directedtoward conduit 59. The suction which is exerted on the fuel in tube 13is therefore considerably lowered.

Thus, whereas the section of the air passage supplied by the opening ofthrottle 5 remains unchanged, the section through. which fuel is allowedto pass and the suction exerted on this fuel are considerably reduced. 1thus ob tain, as soon as the engine is running by itself, a considerablereduction of the richness of the mixtures, whereby it is possible tomake use of extremely rich mixtures when the engine is being driven bythe starter, while obtaining normal mixtures as soon as. the engine hasbeen started and is running by itself.

As the engine is warming up, the driver is led to reduce the action oftheauxiliary starting carburetor, chiefly in order to reduce the speedof the engine. This action is exerted either manually or automaticallyaccording as the construction of the apparatus may be, but the principleremains the same in both cases.

For instance, Fig. 4 shows an intermediate position of disc 43 betweenthe maximum acting position (Fig. l) and the disconnecting position(Fig. 5). This Fig. 4 shows the three radial grooves of disc 43-connecting together only small sections of conduits 14, 50 and 52. itfollows that the section of the passage of fuel is reduced while cam 20enables lever 23 to move in anti-clockwise direction, which graduallyreturns throttle 5 into a position closer to idling running position.

Thus, by moving lever -47 in the clockwise direction, I obtain areduction of the air fiow section, and at the same time a reduction ofthe fuel flow section, which contributes in reducing the speed of theengine.

Fig. 5 shows the disconnecting position for which none of the threeconduits 14, 50 and 52 is in communication, whereas lever 23 is nolonger in contact with cam 20 and occupies a fixed positioncorresponding to the idling running position of the throttle.

The system above described further has the following advantageousfeature.

It is known that as long as disc 43 has not reached the disconnectingposition thereof, when throttle 5 is opened by the throttle pedal actingupon lever 18, the suction exerted in conduit 5'4 drops Whereas, on thecontrary, the main jet system starts feeding fuel into the carburetor.

The supplementary amount normally supplied by conduit 54 is no longersufiicient, due to the reduction of the suction, to give the totalmixture supplied by the carburetor a sufiicient richness and it isnecessary, at this time, to have the amount of fuel supplied'by conduit54 sub stantially increased.

This is what is obtained owing to the provision of piston 58 which,being no longer subjected to the action of a high suction, is returnedby spring 59 against its abutment 60, thus clearing conduit 50 andstopping conduit 52.

In these conditions, the amount of fuel that passes through conduit 54increases substantially and enriches the total mixture supplied by thecarburetor.

I thus obtain, as long as the distributing valve is in operation, andfor all running conditions, an increase of the richness of the mixturewhich is necessary for a good operation of said engine.

Fig. 1a shows a modified construction of the portion of the carburetorincluding piston 58 and the parts which cooperate therewith.

In the modified construction of Fig. 1a, tube 55 is dispensed with.Piston 58 has its open end turned downwardly instead of upwardly as inFig. 1. The outer wall of this piston is provided with an annular groovein the bottom of which is provided a small hole 57a extending throughthe piston hole.

With this arrangement, when piston 58 is held in uppe positi-mn y spring.2i'fu lte rflow?directly-from;conduit? 9 n q-s on itr 5.4; (:whicorresp nds; toifuelzflowina: thr; h the large area; open 561 of tube55in;the con: struction of. Eigg, 1), On thecontraty, when the suctionincreases; in; conduit; 54, piston; 5.8 movesdownfland; this directlarge area: passage is replaced by hole ,57a; (cor-responding to holed-7of; Fig. l): The, operationisithcrefore qu val nt,

In a; general manner,- While I; have-,in; theabove description,disclosed what I' de,em;to; be practical andeificient; embodiments: ofmy inventioni. i would be well understood that I donot; wishtobe;limited thereto; as there; might be; changes, made, in; the;arrangement, disposition and form of the parts withoutdeparting fromtheprinciple-Youth; present invention ascornpnehended within the sen eofthe,accompanyingclaims.

' iSj V 1;. In, a carburetor. includingan induction pipe and a throttlein-saidginduction pipe, an'auxilia-ry starting device which-; comprises, in-combination, a;conduit opening into said nduction pipedownstreamof-saidsthrottle, a source offue;l,-,a conduit leading fromsaidsource, a distributing valvefor co-ntrollingthe-lfiowof-fuelfromsaid source to said induction pipe, said1valve being provided witha-passage arrangedto interconnectsaid two conduits for a given positionof said valve,- meansoperatively connecting said; distributing valvewith said throttle for opening said throttle-from' its maximum closingposition in response to, the bringing of said valve into said position,and means responsive tovariations of the suction in said induction.pipe-downstream of said throttle, for throttling one of said, conduitsfor increases of said suction'above a predetermined:value.

- 2. In acarburetor including an induction pipe and a; throttle. in'saidinduction pipe,an auxiliary startingde:

vicewhich comprises, in combination, aconduit opening into-saidinductionpipeedownwstream of i said throttle, a so rceof; fuel, conduitleadingfrom said source, adistributingvalve for controlling the flow of fuelfrom said source-to said inductionp ipe, said valve being providedwith-a'passage arranged to interconnect said two conduits for a givenposition ofsaid valve, means operatively con: necting saiddistributingvalvewithsaid throttle for opening-saidthrottle from itsmaximum closing position in re-- sponse to the bringing of said valveinto said position, and means; responsive to variations ofthe suction insaid in.-

duction,pipedownstreain of said throttle, for throttlingsaid,firstmentioned conduit for increases'of said-:suc tion above a predeterminedvalue.

3. In a carburetor includingan induction pipe and a throttle in saidinduction pipe, an auxiliary starting evice which comprises; incombination, a conduit opening into said induction pipe downstream ofsaid throttle, a source of ifuel, a conduit leading from said source, adistributing valve for controlling the flow of fuel from said source tosaid induction pipe, said valve. being provided with a passage arrangedto interconnect said two conduits for a given position or" said valve,-means-operatively connecting said} distributingyalve with saidthrottlefor opening-said throttle; ro -n is maximum closing, position inresponseto the bringing of said valve into said position, and a singlemeans, responsive to variations of the suction of said induction pipedownstream of said throttle, for throttling said first mentioned conduitfor increases of said suction above a predetermined value, and forreducing the total suction exerted on the stream of fuel controlled bysaid distributing valve for increases of said first mentioned suctionabove said predetermined value.

4. In a carburetor including a carburetor body provided with an airintake, an induction pipe and a throttle in said induction pipe, anauxiliary carburetor which comprises, in combination, a source of fuel,a conduit leading from said source, a cylindrical housing formed in saidcarburetor body and communicating at one end with said air intake, aconduit starting from the other end of said housing and. Qn ni giimo,saidsindi tiqt nin ad uns ea t. ensaidnht ttten massa ing into thecylindrica-l wal first mentioned end: thereof N i p mentionedi end;vdistributing; valve, fpg; controlling. the, flower fuel from saidsourcesto said induction pipe, said valve-being arrangedrtotconnect,fonaeg-ivempositio there of, both said; first mentioned conduit, andsaid first; men: domed-passage; with said secondm tinned passage, andslide valve means in' said housing, movable-in (response-to suctionvariations; in said second-mentioned conduit for. connecting,- said,s eco-nd mentioned-passage with said second mentionedi conduih throughailarge area. section: of flow while closing; said; firstmentioned'passage. when said. suctionis low and connectingsaid seeondmentionedpas;- sage with said secondmentionedconduit throughsa small, areasection of flow while, openingg s 'd'firstmentioned en saidsuctiontisiaboveva. given,value.v

5. In a carburetor including; a Carburetor body provided with an airintake, aminduction; pipe, and a throt tie in said-induction pipe anaux-iliary, carburetor which, comprises, in, combination, a sourc of,fue1,,a conduitleading from said source, a; cylindriealr housing;formed. in said carburetor body and communicating-at one endwith saidair intake, a conduit. starting from the, otherr end of saidhousingandopeninginto: saidinduction-pipe, downstream of said throttle,twoipassages. in-said-carbu retor body openinginto, the cylindrieahwallof said hous.-. ing, one near the: first mentioned, end thereofthe-other near the second mentioned" end, a; distributing; valve, forcontrolling the flow of fuel from said, source tosaidi; in duction pipe,said; valve'being; arranged to connect,'for a, given-position thereof,both saicLfi st mentioned conduit; andsaid first mentionedpassage ;withsaidv second; men tionedjpassage, means operatively; connecting;saiddise tributing valve with saidthrottle; or opening saidtlirottlerslightly from its maximum; closingposition nF-response to the bringingof'said valve: intogsaid positiomandsslide; valve means insaidhousing,movablesinresponse to suction variations in saidsecond;mentionedconduit for-con: nectinggsaid second mentionedz p assage with saidsecond mentioned conduit through a largeiarea section; of flow; whileclosing ysaid first mentioned-passage:whensaid suction is-lowandconnecting said second mentioned pas:- sage with said secondmentioned conduit through asmall; area section of flow while ope-ninsaid; first mentioned, passage when said'suction is above, 18':

6. In a carburetor including acarbluretorbodyprovided; with an airintake, aninduction pipe andra throttle in said! induction pipe, anauxiliarycarburfltor:which comprises,, in combination, a source of:fuel,, a; conduit leading from; said source, a cylindrical housingiormedin saidrcarbur retor body and communicating at one end with said air;intake, a conduit starting frommg: other end of. S id: housing andopening into said induction.pipeidownstreams of said throttle, twopassages inrsaid5carburetor bodyopen:- ing into the cylindrical wall;of: said housing,,. one-. nea-r; the first mentioned endi'thereofitheother; near: the;s6,c+ 0nd mentioned end, a distributing valve: for;controlling the: flow of .fuel from s aid ;source;to said induction,pipe; said valve being arranged to connect, for a given positionthereof, both said first mentioned conduit and said first mentionedpassage with said second mentioned passage, a tube forming an extensionof said second mentioned conduit into said housing, said tube having itsend located in said housing open and being provided in its side walllocated in said housing with a hole of a section smaller than that ofsaid open end, a piston slidable in said housing in the portion thereofbeyond said tube, said piston having one end adapted to fit on said tubeopen end so as to stop it, said piston being adapted, when in theposition where said end thereof is closing said tube open end, touncover the opening of said first mentioned passage into said hole, and,when it is moved away from said position, to cover'said opening, andspring means hetween said piston and the second mentioned end of saidcasing for urging said piston away from said housing second mentionedend, said spring means being adjusted to oppose the effect of a lowsuction in said second mentioned conduit and to yield to a highersuction.

7. In a carburetor including a carburetor body provided with an airintake, an induction pipe and a throttle in said induction pipe, anauxiliary carburetor which comprises, in combination, a source of fuel,a conduit leading from said source, a cylindrical housing formed in saidcarburetor body and communicating at one end with said air intake, aconduit starting from the other end of said housing and opening intosaid induction pipe downstream of said throttle, two passages in saidcarburetor body opening into the cylindrical wall of said housing, onenear the first mentioned end thereof the other near the second mentionedend, a distributing valve for con trolling the flow of fuel from saidsource to said induction pipe, said valve being arranged to connect, fora given position thereof, both said first mentioned conduit and saidfirst mentioned passage with said second mentioned passage, meansoperatively connecting said distributing valve with said throttle foropening said throttle slightly from its maximum closing position inresponse to the bringing of said valve into said position, a tubeforming an extension of said second mentioned conduit into said housing,said tube having its end located in said housing open and being providedin its side wall located in said housing with a hole of a sectionsmaller than that of said open end, a piston slidable in said housing inthe portion thereof beyond said tube, said piston having one end adaptedto fit on said tube open end so as to stop it, said piston beingadapted, when in the position where said end thereof is closing saidtube open end, to uncover the opening of said first mentioned passageinto said hole, and, when it is moved away from said position, to coversaid opening, and spring means between said piston and the secondmentioned end of said casing for urging said piston away from saidhousing second mentioned end, said spring means being adjusted to opposethe effect of a low suction in said second mentioned conduit and toyield to a higher suction.

8. In a carburetor including a carburetor body pro vided with an airintake, an induction pipe and a throttle in said induction pipe, anauxiliary carburetor which comprises, in combination, a source of fuel,a conduit leading from said source, a cylindrical housing normed in saidcarburetor body and communicating at one end with said air intake, aconduit starting from the other end of said housing and opening intosaid induction pipe downstream of said throttle, two passages in saidcarburetor body opening into the cylindrical wall of said housing, onenear the first mentioned end thereof the other near the second mentionedend, a distributing valve for controlling the flow of fuel from saidsource to said induction pipe, said valve being arranged to connect, fora given position thereof, both said first mentioned conduit and saidfirst mentioned passage with said second mentioned passage, a pistonslidable in said housing, the end of said piston nearer to the secondmentioned end of said housing being open, and the opposite end beingclosed, the cylindrical wall of said piston being provided with a smallhole adapted to register with said second mentioned passage when saidpiston is in its end position toward said second mentioned end of saidcasing, the length of said piston being such that it then uncovers saidfirst mentioned passage whereas it covers it when said piston is movedaway from the second mentioned end of said housing, and spring meansbetween said piston and the second mentioned end of said casing forurging said piston away from said housing second mentioned end, saidspring means being adjusted to oppose the effect of a low suction insaid second mentioned conduit and to yield to a higher suction.

9. in a carburetor including a carburetor body provided with an airintake, an induction pipe and a throttle in said induction pipe, anauxiliary carburetor which comprises, in combination, a source of fuel,a conduit leading from said source, a cylindrical housing formed in saidcarburetor body and communicating at one end with said air intake, aconduit starting from the other end of said housing and opening intosaid induction pipe downstream of said throttle, two passages in saidcarburetor body opening into the cylindrical wall of said housing, onenear the first mentioned end thereof the other near the second mentionedend, a distributing valve for controlling the flow of fuel from saidsource to said induction pipe, said valve being arranged to connect, fora given position thereof, both said first mentioned conduit and saidfirst mentioned passage with said second mentioned passage, meansoperatively connecting said distributing valve with said throttle foropening said throttle slightly from its maximum closing position inresponse to the bringing of said valve into said position, a pistonslidable in said housing, the end of said piston nearer to the secondmentioned end of said housing being open, and the opposite end beingclosed, the cylindrical Wall of said piston being provided with a smallhole adapted to register with said second mentioned passage when saidpiston is in its end position toward said second mentioned end of saidcasing, the length of said piston being such that it then uncovers saidfirst mentioned passage whereas it covers it when said piston is movedaway from the second mentioned end of said housing, and spring meansbetween said piston and the second mentioned end of said casing forurging said piston away from said housing second mentioned end, saidspring means being adjusted to oppose the effect of a low suction insaid second mentioned conduit and to yield to a higher suction.

References Cited in the file of this patent UNITED STATES PATENTS1,898,958 Heitger Feb. 21, 1933 1,945,199 Mock et a1. Jan. 30, 19342,569,782 Sloane Oct. 2, 1951 2,621,911 Lindsteadt Dec. 16, 1952 FOREIGNPATENTS 397,073 Great Britain Aug. 17, 1933 832,810 Germany Feb. 28,1952

